A road network automatic integration method and device, electronic equipment and storage medium

Abstract

The embodiment of the present application provides a method and device for automatic road network integration, an electronic device and a storage medium, which belongs to the field of surveying and mapping geographic information technology. The method includes: marking characteristic roads; deleting road mesh hanging lines that are less than the minimum road length threshold and do not belong to characteristic roads to obtain first road network structured information; deleting the first candidate road with the lowest road grade that does not belong to the characteristic road to obtain second road network structured information; deleting the second candidate road with the lowest road grade that does not belong to the characteristic road to obtain third road network structured information; based on the third road network structured information, mesh merging is performed to obtain target mesh structured information and target road network structured information. The embodiment of the present application comprehensively extracts a structured road network, and after integration, the road network shape structural characteristics and road network line density differences are reasonably maintained, thereby improving the efficiency and rationality of road network integration and reducing the workload of manual road network integration.

Description

Technical Field

[0001] The present application relates to the field of surveying and mapping geographic information technology, and in particular to a method and device for automatic road network integration, an electronic device, and a storage medium. Background Art

[0002] In related technologies, traditional road network comprehensive models focus more on considering geometric comprehensive constraints when selecting roads, and pay less attention to the impact of road attribute values and other geographical factors on the comprehensive selection of roads. They also pay insufficient attention to the characteristics of the road network, and the automatic comprehensive automation of roads is insufficient, which affects the rationality and efficiency of comprehensive road selection.

[0003] In summary, the technical problems existing in the relevant technologies need to be improved. Summary of the Invention

[0004] The main purpose of the embodiments of this application is to propose a method and device for automatic road integration, an electronic device and a storage medium, aiming to extract a structured road network, better maintain the characteristics of the road network and the differences in road mesh density, and improve the efficiency and rationality of road integration.

[0005] To achieve the above objectives, an embodiment of the present application provides a method for automatic road integration, the method comprising the following steps:

[0006] Marking characteristic roads based on initial road network structured information, wherein the initial road network structured information includes road mesh boundary lines and road mesh suspension lines;

[0007] Deleting the road mesh suspension lines that are shorter than a minimum road length threshold and do not belong to the characteristic roads in the initial road network structured information, to obtain first road network structured information after deletion;

[0008] marking a first candidate road based on the initial mesh structured information, the first road network structured information, and a road mesh line density threshold, deleting the first candidate road having the lowest road grade in the first road network structured information and not belonging to the feature road, to obtain second road network structured information after deletion, wherein the initial road network structured information includes road grade information and road length information;

[0009] marking a second candidate road based on the initial mesh structured information and the second road network structured information, deleting the second candidate road having the lowest road grade in the second road network structured information and not belonging to the feature road, to obtain third road network structured information after deletion;

[0010] Mesh merging is performed based on the third road network structured information to obtain target mesh structured information and target road network structured information.

[0011] To achieve the above objectives, another aspect of the present application provides an automatic road network integration device, the device comprising:

[0012] a marking module, configured to mark characteristic roads based on initial road network structured information, wherein the initial road network structured information includes road mesh boundary lines and road mesh suspension lines;

[0013] A first integration module is configured to delete the road mesh hanging lines that are shorter than a minimum road length threshold and do not belong to the characteristic roads in the initial road network structured information, thereby obtaining first road network structured information after deletion;

[0014] a second integration module, configured to mark first candidate roads based on the initial mesh structured information, the first road network structured information, and a road mesh line density threshold, and delete the first candidate roads having the lowest road grade in the first road network structured information and not belonging to the feature roads, to obtain second road network structured information after deletion, wherein the initial road network structured information includes road grade information and road length information;

[0015] a third integration module, configured to mark second candidate roads based on the initial mesh structured information and the second road network structured information, delete the second candidate roads having the lowest road grade in the second road network structured information and not belonging to the feature roads, and obtain third road network structured information after deletion;

[0016] The merging module is used to merge meshes based on the third road network structured information to obtain target mesh structured information and target road network structured information.

[0017] To achieve the above-mentioned purpose, another aspect of an embodiment of the present application provides an electronic device, which includes a memory and a processor, wherein the memory stores a computer program, and the processor implements the above-mentioned method when executing the computer program.

[0018] To achieve the above objectives, another aspect of an embodiment of the present application provides a computer-readable storage medium, wherein the computer-readable storage medium stores a computer program, and when the computer program is executed by a processor, the method described above is implemented.

[0019] The embodiments of the present application include at least the following beneficial effects: the present application provides a method and apparatus for automatic synthesis of road networks, an electronic device and a storage medium, which is conducive to maintaining the characteristics of the road network and understanding the functional structure of the road network by marking characteristic roads based on the initial road network structured information; deleting the road mesh hanging lines that are less than the minimum road length threshold and do not belong to the characteristic roads in the initial road network structured information, obtaining the first road network structured information after deletion, retaining the main road structure and reducing complexity; marking the first candidate road based on the initial mesh structured information, the first road network structured information and the road mesh line density threshold, deleting the first candidate road with the lowest road grade in the first road network structured information and not belonging to the characteristic road, obtaining the second road network structured information after deletion, which is conducive to streamlining the road network structure and maintaining the road network structure. The density difference of road networks is improved, and the rationality of road integration is improved; the second candidate road is marked based on the initial mesh structured information and the second road network structured information, and the second candidate road with the lowest road grade and not belonging to the feature road in the second road network structured information is deleted to obtain the deleted third road network structured information, and the road network structure is streamlined; the mesh is merged based on the third road network structured information to obtain the target mesh structured information and the target road network structured information, which is conducive to reducing redundant roads and meshes and making the road network more streamlined and effective. After integration, the structural characteristics of the road network and the difference in road network line density are reasonably maintained, and the data quality such as the correctness of the topological relationship between roads, the integrity of attribute values and the geometric accuracy is good, which improves the efficiency of road network integration and optimizes the rationality of road network integration, and greatly reduces the workload of manual integration of road networks. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 is a flow chart of the road network automatic integration method provided by an embodiment of the present application;

[0021] Figure 2 yes Figure 1 Flowchart of step S103 in FIG.

[0022] Figure 3 yes Figure 1 Flowchart of step S105 in FIG.

[0023] Figure 4 This is a flow chart of the data preprocessing steps of the road network automatic integration method provided in an embodiment of the present application;

[0024] Figure 5 This is a specific implementation flow chart of the road network automatic integration method provided in the embodiment of the present application when it is applied to the road automatic comprehensive selection system;

[0025] Figure 6This is a Delaunay triangle classification and midline extraction connection diagram provided by an embodiment of the present application;

[0026] Figure 7 This is a schematic diagram of the road centerline extraction process provided by an embodiment of the present application;

[0027] Figure 8 This is a road centerline rendering provided by an embodiment of the present application;

[0028] Figure 9 This is a schematic diagram of a road fusion network provided in an embodiment of the present application;

[0029] Figure 10 This is a schematic diagram of a road link break process provided by an embodiment of the present application;

[0030] Figure 11 This is a flowchart of pseudo node detection and automatic linking processing provided by an embodiment of the present application;

[0031] Figure 12 This is a schematic diagram of road breakpoint connections provided by an embodiment of the present application;

[0032] Figure 13 This is the structured information representation of the road mesh boundary lines and suspension lines provided in the embodiment of the present application;

[0033] Figure 14 This is the intended representation of the road mesh structured information provided by the embodiment of the present application;

[0034] Figure 15 This is a road mesh structure diagram provided in an embodiment of the present application;

[0035] Figure 16 This is a schematic diagram of road network data at various scales provided in the embodiments of the present application;

[0036] Figure 17 This is a schematic diagram of the positional relationship between the simplified road and the integrated front-source two-lane road provided in the embodiment of the present application;

[0037] Figure 18 This is an enlarged schematic diagram of the positional relationship between the simplified road and the integrated front-source two-lane road provided in an embodiment of the present application;

[0038] Figure 19 is a road network attribute table after integration provided in an embodiment of the present application;

[0039] Figure 20 This is a schematic diagram comparing road attribute data before and after the road network integration provided by the embodiment of the present application;

[0040] Figure 21 This is a flowchart for implementing a constraint-based face weight graph theory road network selection model provided in an embodiment of the present application;

[0041] Figure 22 It is a structural diagram of the automatic road network integration device provided in an embodiment of the present application;

[0042] Figure 23 This is a schematic diagram of the hardware structure of the electronic device provided in an embodiment of the present application. DETAILED DESCRIPTION

[0043] In order to make the purpose, technical solutions and advantages of the present application clearer, the present application is further described in detail below with reference to the accompanying drawings and examples. It should be understood that the specific embodiments described herein are only used to explain the present application and are not intended to limit the present application. When the following description refers to the drawings, unless otherwise indicated, the same numbers in different drawings represent the same or similar elements. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with the embodiments of the present application. They are merely examples of devices and methods consistent with some aspects of the embodiments of the present application as detailed in the appended claims.

[0044] It will be understood that the terms "first", "second", etc. used in this application may be used herein to describe various concepts, but unless otherwise specified, these concepts are not limited by these terms. These terms are only used to distinguish one concept from another. For example, without departing from the scope of the embodiments of the present application, the first information may also be referred to as the second information, and similarly, the second information may also be referred to as the first information. Depending on the context, the words "if" and "if" as used herein may be interpreted as "at the time of" or "when" or "in response to determining".

[0045] The terms "at least one", "plurality", "each", "any", etc. used in this application include "at least one", "two" or more, "plurality" or "each", "any" or "any one", "each" or "any one" as used herein.

[0046] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art to which this application pertains. The terms used herein are for the purpose of describing the embodiments of this application only and are not intended to limit this application.

[0047] Before explaining the embodiments of the present application in detail, some of the nouns and terms involved in the embodiments of the present application are first explained. The nouns and terms involved in the embodiments of the present application are subject to the following explanations.

[0048] 1) Delaunay triangulation is a triangulation method. Given a set of points on a plane, Delaunay triangulation can connect these points into triangles so that there are no other points inside the circumcircle of each triangle.

[0049] 2) Automatic road network synthesis refers to the automation of simplification, generalization, and optimization of road networks in multi-scale maps through algorithms and programs, enabling the automatic derivation of various small-scale road data from large-scale road data to meet the mapping needs of maps of different scales.

[0050] In related technologies, traditional road network comprehensive models focus more on considering geometric comprehensive constraints when selecting roads, and pay less attention to the impact of road attribute values and other geographical factors on the comprehensive selection of roads. They also pay insufficient attention to the characteristics of the road network, and the automatic comprehensive automation of roads is insufficient, which affects the rationality and efficiency of comprehensive road selection.

[0051] In summary, the technical problems existing in the relevant technologies need to be improved.

[0052] In view of this, embodiments of the present application provide a method, apparatus, device, and medium for automatic road network integration. This solution helps maintain the characteristics of the road network and understand the functional structure of the road network by marking characteristic roads based on initial road network structured information; deletes road mesh hanging lines that are less than a minimum road length threshold and do not belong to characteristic roads in the initial road network structured information to obtain deleted first road network structured information, retaining the main road structure and reducing complexity; marks first candidate roads based on the initial mesh structured information, the first road network structured information, and the road mesh line density threshold, deletes the first candidate road with the lowest road grade and that does not belong to the characteristic road in the first road network structured information, and obtains deleted second road network structured information, which helps streamline the road network structure, maintain road mesh density differences, and improve the rationality of road integration; Based on the initial mesh structured information and the second road network structured information, the second candidate road is marked, and the second candidate road with the lowest road grade and not belonging to the feature road in the second road network structured information is deleted to obtain the deleted third road network structured information, thereby streamlining the road network structure. Based on the third road network structured information, meshes are merged to obtain target mesh structured information and target road network structured information, which is conducive to reducing redundant roads and meshes and making the road network more streamlined and effective. After integration, the structural characteristics of the road network and the differences in road network line density are reasonably maintained, and the data quality such as the correctness of the topological relationship between roads, the integrity of attribute values and the geometric accuracy is good, thereby improving the efficiency of road network integration and optimizing the rationality of road network integration, and greatly reducing the workload of manual integration of road networks.

[0053] The automatic road network synthesis method provided in the embodiment of the present application relates to the field of surveying and mapping geographic information. The automatic road network synthesis method provided in the embodiment of the present application can be applied to a terminal, can be applied to a server, or can be software running in a terminal or a server. In some embodiments, the terminal can be a smart phone, a tablet computer, a laptop computer, a desktop computer, a smart speaker, a smart watch, and a car terminal, etc., but is not limited to this; the server side can be configured as an independent physical server, or as a server cluster or distributed system composed of multiple physical servers, or as a cloud server that provides basic cloud computing services such as cloud services, cloud databases, cloud computing, cloud functions, cloud storage, network services, cloud communications, middleware services, domain name services, security services, CDN, and big data and artificial intelligence platforms. The server can also be a node server in a blockchain network; the software can be an application that implements the automatic road network synthesis method, etc., but is not limited to the above forms.

[0054] The present application can be used in many general or special computer system environments or configurations. For example: personal computers, server computers, handheld or portable devices, tablet devices, multiprocessor systems, microprocessor-based systems, set-top boxes, programmable consumer electronics, network PCs, minicomputers, mainframe computers, distributed computing environments including any of the above systems or devices, and the like. The present application can be described in the general context of computer-executable instructions executed by a computer, such as program modules. Generally, program modules include routines, programs, objects, components, data structures, and the like that perform specific tasks or implement specific abstract data types. The present application can also be practiced in distributed computing environments in which tasks are performed by remote processing devices connected via a communication network. In a distributed computing environment, program modules can be located in local and remote computer storage media, including storage devices.

[0055] Figure 1 This is an optional flowchart of the road network automatic integration method provided in the embodiment of the present application. Figure 1 The method may include but is not limited to steps S101 to S105.

[0056] Step S101: marking characteristic roads based on initial road network structured information.

[0057] Specifically, the initial road network structured information includes road mesh boundary lines and road mesh suspension lines.

[0058] In some embodiments, initial road network structured information is extracted from source road data.

[0059] Specifically, the process involves obtaining source road data; extracting road centerlines based on the source road data using the Delaunay triangulation method; fusing the road centerlines of multiple road layers to obtain fused road data; performing link breaking, deleting overlapping lines, and performing road breakpoint processing on the fused road data to obtain original road information; converting road line elements into a road mesh surface based on the original road information, and determining the road mesh and road mesh boundary lines; determining the internal and external suspension lines of the road mesh based on the original road information and the road mesh; and constructing a topological relationship model based on the original road information, the road mesh, the road mesh boundary lines, the internal and external suspension lines of the road mesh. The topological relationship model includes initial road network structured information and initial mesh structured information, with the road mesh referring to the road mesh surface.

[0060] Optionally, a graph theory model is used to select and mark characteristic roads based on the initial road network structured information through attribute value semantic constraints.

[0061] In some embodiments, a spatial analysis method is used to analyze the initial road network structured information to select and mark characteristic roads.

[0062] It is understood that in response to the first instruction, the initial road network structured information is displayed on the map page, and in response to the road selection instruction, the characteristic road selected by the user is displayed on the map page. The first instruction is triggered when the map page is opened or refreshed, and the first instruction is used to display the map page, and the road selection instruction is triggered when the user selects a characteristic road.

[0063] In this embodiment, marking characteristic roads based on the initial road network structured information is beneficial to maintaining the characteristics of the road network, understanding the functional structure of the road network, and providing data support for subsequent road selection.

[0064] Step S102: Deleting the road mesh hanging lines that are shorter than the minimum road length threshold and do not belong to the characteristic roads from the initial road network structured information, thereby obtaining the deleted first road network structured information.

[0065] Specifically, the road mesh suspension lines include road mesh internal suspension lines and road mesh external suspension lines.

[0066] It is understandable that for the suspension line roads outside the road mesh, considering that the external suspension lines of the road mesh are the main bridges connecting the comprehensive regional road network and another regional road network, all the external suspension lines of the road mesh are retained during the selection process.

[0067] In some embodiments, the external hanging lines of the road mesh in the initial road network structured information are retained; the internal hanging lines of the road mesh that are less than the minimum road length threshold and do not belong to the characteristic roads in the initial road network structured information are deleted to obtain the first road network structured information after deletion.

[0068] Specifically, the road mesh is traversed sequentially to find the minimum hanging line in the mesh, and it is determined whether the length of the corresponding hanging line is less than the comprehensive threshold (i.e., the minimum road length threshold). If so, the road feature is retained and the minimum hanging line in the mesh is searched again. Otherwise, the road mark is deleted.

[0069] The minimum road length threshold can be determined by the user or automatically by the system.

[0070] For example, for the internal hanging lines of the road mesh, according to the shortest road length expression conditions of the corresponding mapping specifications of the comprehensive target scale (for example, according to the provisions of the basic scale map compilation specifications, the minimum expression length on the 1:25000 topographic map road map is 1 cm, that is, the actual road length is 250m), the road lines that are shorter than the standard length threshold and are not feature roads will be deleted.

[0071] In this embodiment, the road mesh hanging lines that are less than the minimum road length threshold and do not belong to the characteristic roads in the initial road network structured information are deleted to obtain the first road network structured information after deletion, which is conducive to retaining the main road structure, reducing complexity and improving processing efficiency.

[0072] Step S103: Mark the first candidate road based on the initial mesh structured information, the first road network structured information, and the road mesh line density threshold, delete the first candidate road with the lowest road grade in the first road network structured information and which does not belong to the feature road, and obtain the deleted second road network structured information.

[0073] Specifically, the initial road network structured information includes road grade information and road length information, and the first candidate road is a road in a mesh whose road mesh line density is greater than a road mesh line density threshold.

[0074] In some embodiments, it is determined whether the number of roads in the first road network structured information is greater than the square root model comprehensive threshold (i.e., the target road number). If so, the road mesh line density is calculated, and the mesh whose road mesh line density exceeds the road mesh line density threshold is determined, and the road contained in the mesh is used as the first candidate road.

[0075] The number of target roads may be determined by the user or automatically by the system; the road mesh line density threshold may also be determined by the user or automatically by the system, without limitation thereto.

[0076] It can be understood that if the number of roads is less than or equal to the square root model comprehensive threshold, the road selection is terminated.

[0077] Optionally, the first candidate road with the lowest road grade, the shortest length, and not belonging to the feature road in the first road network structured information is deleted to obtain the deleted second road network structured information.

[0078] In some embodiments, the current road mesh line density of each mesh is calculated based on the initial mesh structured information and the first road network structured information; the mesh whose current road mesh line density is greater than the road mesh line density threshold is determined as a candidate mesh, the hanging line in the candidate mesh is marked as the first candidate road, and the first candidate road with the lowest road grade is used as the first pre-selected road.

[0079] Furthermore, if the first pre-selected roads include only a single road and the first pre-selected road does not belong to a feature road, the first pre-selected road is deleted from the first road network structured information to obtain the deleted second road network structured information.

[0080] Optionally, if the first pre-selected roads include multiple roads, the road with the shortest length among the first pre-selected roads is determined as the first selected road. If the first selected road does not belong to the feature road, the first selected road is deleted from the first road network structured information to obtain the deleted second road network structured information.

[0081] For example, the road mesh line density is judged according to the mapping specifications. For the road mesh with a line density greater than the standard threshold, the hanging road with the smallest internal level and the shortest length is searched. If the hanging road found is not a feature road, its mark is deleted.

[0082] In this embodiment, the first candidate road is marked based on the initial mesh structured information, the first road network structured information and the road mesh line density threshold, and the first candidate road with the lowest road grade and not belonging to the feature road in the first road network structured information is deleted to obtain the deleted second road network structured information, which is conducive to streamlining the road network structure, maintaining the difference in road mesh density, and improving the rationality of road integration.

[0083] Step S104: Mark the second candidate road based on the initial mesh structured information and the second road network structured information, delete the second candidate road with the lowest road grade in the second road network structured information and which does not belong to the feature road, and obtain the deleted third road network structured information.

[0084] Specifically, the initial mesh structure information includes the mesh area, and the second candidate road is the mesh boundary line of the road mesh with the smallest mesh area.

[0085] In some embodiments, it is determined whether the number of roads in the second road network structured information is greater than the square root model comprehensive threshold (i.e., the target road number). If so, the road mesh with the smallest mesh area is determined based on the initial mesh structured information; based on the second road network structured information, the boundary line of the road mesh with the smallest mesh area is marked (or determined) as the second candidate road.

[0086] Furthermore, the second candidate road with the lowest road grade is used as the second pre-selected road.

[0087] Optionally, if the second pre-selected roads include only a single road and the second pre-selected road does not belong to a feature road, the second pre-selected road is deleted from the second road network structured information to obtain the deleted third road network structured information; if the second pre-selected roads include multiple roads, the road with the shortest length among the second pre-selected roads is determined as the second selected road. If the second selected road does not belong to a feature road, the second selected road is deleted from the second road network structured information to obtain the deleted third road network structured information.

[0088] In this embodiment, the second candidate road is marked based on the initial mesh structured information and the second road network structured information, and the second candidate road with the lowest road grade and not belonging to the feature road in the second road network structured information is deleted to obtain the deleted third road network structured information. This is conducive to streamlining the road network structure, reducing the computational complexity of subsequent processing, and improving the efficiency and accuracy of road integration.

[0089] Step S105 : merging meshes based on the third road network structured information to obtain target mesh structured information and target road network structured information.

[0090] In some embodiments, mesh merging is performed to merge meshes on both sides of a deleted road into one, simplifying the network structure. The merged road network structure reflects the final road connectivity and functional distribution, making the target road network more compact.

[0091] Optionally, the meshes on both sides of the deleted road are merged; the topological structured information of the meshes is updated; the number of remaining roads is calculated, and if the target number of roads is reached, the target mesh structured information and the target road network structured information are obtained.

[0092] It is understandable that if the target number of roads is not reached, the process returns to step S104.

[0093] In some embodiments, mesh merging is performed based on the third road network structured information to obtain the current mesh structured information and the current road network structured information after mesh merging; the target road number is obtained, and the current road number of the current road network structured information is calculated; if the current road number is greater than the target road number, the current road network structured information is used as the second road network structured information, and the current mesh structured information is used as the initial mesh structured information, and the step of marking the road as the second candidate road based on the initial mesh structured information and the second road network structured information is returned until the current road number is less than or equal to the target road number; if the current road number is less than or equal to the target road number, the current mesh structured information is used as the target mesh structured information, and the current road network structured information is used as the target road network structured information.

[0094] This involves searching for another adjacent road network to merge, merging the two networks to create a new feature network for storage, completing the attribute information such as the boundary between the new and old faces, and finding the starting point of the boundary line to be deleted. A check is performed to determine if the starting point is a graph theory breakpoint. If so, the starting point graph theory breakpoint is connected to integrate the attribute information, updating the merged road network boundary information, and then finding the end point of the boundary line to be deleted. If not, the end point of the boundary line to be deleted is directly found.

[0095] Next, determine whether the endpoint is a graph breakpoint. If so, connect the graph breakpoint at the endpoint, integrate the attribute information, update the merged road network boundary information, and then determine whether the number of remaining roads is greater than the square root model comprehensive threshold. If not, directly determine whether the number of remaining roads is greater than the square root model comprehensive threshold. If the number of remaining roads is less than or equal to the square root model comprehensive threshold, the comprehensive road selection is completed. Otherwise, return to the step of finding the road network with the smallest area.

[0096] Steps S101 to S105 shown in the embodiment of the present application help maintain the characteristics of the road network by marking characteristic roads based on the initial road network structured information; deleting road mesh hanging lines that are less than the minimum road length threshold and do not belong to characteristic roads in the initial road network structured information to obtain the first road network structured information after deletion, retaining the main road structure and reducing complexity; marking the first candidate road based on the initial mesh structured information, the first road network structured information, and the road mesh line density threshold, deleting the first candidate road with the lowest road grade and not belonging to the characteristic road in the first road network structured information, obtaining the second road network structured information after deletion, maintaining the difference in road mesh density and improving the rationality of road integration; Based on the initial mesh structured information and the second road network structured information, the second candidate road is marked, and the second candidate road with the lowest road grade and not belonging to the feature road in the second road network structured information is deleted to obtain the deleted third road network structured information; meshes are merged based on the third road network structured information to obtain target mesh structured information and target road network structured information, which is conducive to reducing redundant roads and meshes and making the road network more streamlined and effective. After integration, the road network structural characteristics and road network line density differences are reasonably maintained, and the data quality such as the correctness of the topological relationship between roads, the integrity of attribute values and the geometric accuracy is good, which improves the efficiency of road network integration and optimizes the rationality of road network integration, and greatly reduces the workload of manual integration of road networks.

[0097] See also Figure 2 In some embodiments, step S103 may include but is not limited to steps S201 to S204:

[0098] Step S201 : Calculate the current road network line density of each mesh based on the initial mesh structure information and the first road network structure information.

[0099] It can be understood that the initial mesh structure information includes at least one mesh.

[0100] In step S201 of some embodiments, it is determined whether the number of first roads in the first road network structured information is greater than the square root model comprehensive threshold. If so, the current road mesh line density of each mesh is calculated. If not, the selection is terminated.

[0101] The square root model comprehensive threshold value may be defined by the user, or may use a system default value or be automatically determined by the system, without limitation thereto.

[0102] In step S202, a mesh whose current road mesh line density is greater than a road mesh line density threshold is determined as a candidate mesh, the road with the lowest road grade among the candidate meshes is marked as the first candidate road, and the first candidate road with the lowest road grade is used as the first pre-selected road.

[0103] In step S202 of some embodiments, meshes whose current road mesh line density is greater than a road mesh line density threshold are determined as candidate meshes.

[0104] It is understandable that the candidate mesh can be a single mesh or multiple meshes, and this application does not limit this.

[0105] Furthermore, the road in the candidate mesh is marked (or determined) as the first candidate road, and the first candidate road with the lowest road grade is used as the first pre-selected road.

[0106] It is understandable that the first pre-selected road may be a single road or multiple roads, and this application does not limit this.

[0107] Step S203: If the first pre-selected roads include only a single road and the first pre-selected road does not belong to a feature road, the first pre-selected road is deleted from the first road network structured information to obtain the deleted second road network structured information.

[0108] In step S203 of some embodiments, a single first pre-selected road that does not belong to a characteristic road is deleted, and the second road network structured information is obtained after the deletion.

[0109] In step S204, if the first pre-selected roads include multiple roads, the road with the shortest length among the first pre-selected roads is determined as the first selected road. If the first selected road is not a feature road, the first selected road is deleted from the first road network structured information to obtain the deleted second road network structured information.

[0110] In step S204 of some embodiments, if the first pre-selected road includes multiple roads, a first selected road with the shortest length is selected from the first pre-selected roads.

[0111] Furthermore, the first selected roads that do not belong to the characteristic roads are deleted, and the second road network structured information is obtained after the deletion.

[0112] See also Figure 3 In some embodiments, step S105 may include but is not limited to steps S301 to S304:

[0113] Step S301: merging meshes based on the third road network structured information to obtain current mesh structured information and current road network structured information after the mesh merging.

[0114] In step S301 of some embodiments, the meshes on both sides of the deleted road are merged, and the topological structured information of the meshes is updated.

[0115] Step S302: Obtain the target road quantity and calculate the current road quantity of the current road network structured information.

[0116] It is understandable that the target road number can be customized by the user, or automatically determined by the system or using the system default value.

[0117] In step S302 of some embodiments, the current number of roads in the current road network structured information after mesh merging is calculated.

[0118] Step S303: If the current number of roads is greater than the target number of roads, the current road network structured information is used as the second road network structured information, and the current mesh structured information is used as the initial mesh structured information, and the process returns to the step of marking the second candidate road based on the initial mesh structured information and the second road network structured information, until the current number of roads is less than or equal to the target number of roads.

[0119] It is understandable that if the current number of roads is greater than the target number of roads, the current road network structured information does not meet the system requirements and road integration needs to be continued.

[0120] Furthermore, the current road network structured information is used as the second road network structured information, and the current mesh structured information is used as the initial mesh structured information, and the step of marking the road as the second candidate road based on the initial mesh structured information and the second road network structured information is returned until the current number of roads is less than or equal to the target number of roads.

[0121] Step S304: If the current number of roads is less than or equal to the target number of roads, the current mesh structured information is used as the target mesh structured information, and the current road network structured information is used as the target road network structured information.

[0122] In step S304 of some embodiments, if the current number of roads is less than or equal to the target number of roads, the road selection is completed, and the current mesh structured information is used as the target mesh structured information, and the current road network structured information is used as the target road network structured information.

[0123] See also Figure 4 In some embodiments, the road network automatic integration method provided in the embodiments of the present application further includes a data preprocessing step, which may include but is not limited to steps S401 to S403:

[0124] Step S401: Acquire source road data.

[0125] In step S401 of some embodiments, source road data is acquired from a multi-source database or a multi-source data interface.

[0126] Step S402 : extracting the road centerline based on the source road data using the Delaunay triangulation method.

[0127] In step S402 of some embodiments, a Delaunay triangulation is constructed to generate a road centerline.

[0128] Optionally, a point-by-point interpolation method is used to generate a Delaunay triangulation network, and a Delaunay triangulation is performed on the two-lane road area.

[0129] Furthermore, Delaunay triangles are classified and identified, and the triangles generated by the subdivision are divided into three categories during the network construction process.

[0130] In some embodiments, the centerline is extracted based on the Delauany triangulation, the road at the intersection is straightened, and the centerline of the road is smoothed.

[0131] Step S403: Fusing the road centerlines of multiple road layers to obtain fused road data.

[0132] In step S403 of some embodiments, road fusion networking is implemented, and an empty feature class is generated using all road layer feature classes to be networked as templates (mathematical basis and corresponding fields); different layer feature classes are traversed one by one, and the corresponding elements are added to the newly established empty feature class, and the corresponding attribute information is matched and updated; a new FROMLAYER field is created, and the name value of the road element source layer is written into it to obtain fused road data.

[0133] Step S404 : performing link breaking processing, overlapping line deletion processing, and road breakpoint processing on the fused road data to obtain original road information.

[0134] In step S404 of some embodiments, in order to meet the requirements of the road network selection model based on the constraint surface weighted graph theory, the boundary lines of the merged multi-source road mesh are broken, and the corresponding two road elements at the intersection are disconnected.

[0135] Furthermore, the overlapping line deletion process is implemented, a line feature buffer surface is generated based on the cluster tolerance, and the overlapping features (i.e., overlapping road lines) that are completely contained are identified through spatial query, and the overlapping features are deleted.

[0136] In some embodiments, corresponding roads with pseudo nodes or roads without pseudo nodes that are interrupted are connected at the breakpoints to form a new road network feature class, and attribute values of the connected road networks are integrated.

[0137] Step S405 : converting the road line elements into a road mesh surface based on the original road information, and determining the road mesh and the road mesh boundary line.

[0138] Specifically, the road mesh is the road mesh surface.

[0139] In some embodiments, converting a road line element into a road mesh surface specifically includes the following steps:

[0140] 1) Use the DataManagementTools.FeatureToPolygon interface tool in ArcEngine to convert the road line feature class into a road mesh feature class;

[0141] 2) Add the BOUNADRY, AREA, and DENSITY fields to the newly generated road mesh feature class:

[0142] 3) Traverse the generated road mesh, calculate the area value of the corresponding road mesh and store it in the AREA area field attribute value;

[0143] 4) Use ArcEngine geometric feature attributes to extract the boundary lines of the road mesh, perform buffer analysis on the boundary lines of the road mesh, and generate buffer surface features;

[0144] 5) Perform overlay analysis on the buffer surface features and the road mesh line feature class boundary lines, find the road mesh boundary line corresponding to each mesh surface feature, and store the ID of the corresponding road mesh road boundary line in the BOUNADRY field attribute value to facilitate tracking and updating of road mesh boundary lines when merging meshes in the graph theory model;

[0145] 6) Calculate the road density of the road mesh and store the corresponding calculated value in the DENSITY field attribute value.

[0146] Step S406: determining the road mesh internal suspension line and the road mesh external suspension line based on the original road information and the road mesh.

[0147] In step S406 of some embodiments, the suspension lines of the roads inside and outside the road mesh are determined, and the suspension lines of the roads are divided into suspension lines inside the road mesh and suspension lines outside the road mesh.

[0148] Step S407 : constructing a topological relationship model based on the original road information, the road mesh, the road mesh boundary lines, the road mesh internal suspension lines, and the road mesh external suspension lines.

[0149] Specifically, the topological relationship model includes initial road network structured information and initial mesh structured information.

[0150] Furthermore, a new feature class is created to store the processing results (i.e., road mesh, road mesh boundary lines, road mesh internal suspension lines, and road mesh external suspension lines). A new FROM field is created to track the features in the comprehensive processing process, record the source information of the features, establish an ID relationship between the features in the new feature class and the original features (i.e., the original road information), and achieve dynamic integration through attribute mapping rules. Numerical attributes are averaged, and non-numeric attributes are stored together.

[0151] In step S407 of some embodiments, a topological relationship model is constructed, which includes the boundary lines of the road mesh and the topological relationship formed by the suspended roads.

[0152] Taking the automatic comprehensive road selection system as an example, Figure 5 This is a specific implementation flow chart of the road network automatic integration method provided in the embodiment of the present application when it is applied to the road automatic comprehensive selection system. Figure 5 The method may include, but is not limited to, the following steps:

[0153] Step 1: Extract road centerline.

[0154] Construct a Delaunay triangulation to generate the road centerline. Specifically, this paper uses Delaunay triangulation to extract the road centerline. The specific process is as follows:

[0155] (1) Delaunay triangulation is performed on the two-lane road area. Specifically, the point-by-point interpolation method mentioned above is used to generate the Delaunay triangulation network.

[0156] (2) Classify and identify Delaunay triangles, and divide the generated triangles into three categories during the network construction process. For example, the Delaunay triangle classification and midline extraction connection diagram is as follows Figure 6 shown.

[0157] Type I triangles have only one adjacent triangle on one side, Type II triangles have two adjacent triangles on two sides, and Type III triangles have three adjacent triangles on all three sides. Type I triangles are primarily found at road entrances and exits, Type III triangles are found at road intersections, and those found elsewhere are classified as Type II triangles.

[0158] Furthermore, to achieve road centerline network construction, when extracting road centerlines, point-to-point line construction is performed as follows: for Type I triangles, the midpoint of the only adjacent edge is connected to the vertex of the corresponding triangle; for Type II triangles, the midpoints of two adjacent edges are connected; and for Type III triangles, the midpoints of three edges are connected to the centroid. Adjacent edges are the common edges of two adjacent triangles. The search begins with Type III triangles and ends with either Type I or Type III triangles, obtaining a network edge. This continues until all Type III triangles are processed. The search then begins again with Type I triangles and ends with Type I triangles, thus extracting the road centerline network.

[0159] Optionally, straighten intersection road lines: During the network construction process, the centerlines of the roads extracted from the triangles at T-junctions need to be straightened. The main method is to first find the intersection points, then trim the straight lines at the intersections by a certain length. The angles of the remaining lines after trimming are compared. When the angles of the two lines meet a certain range, the two lines are connected and merged into a single line. In the case of intersections, the intersection points are used as nodes of the network, ultimately forming the road network.

[0160] In some embodiments, road smoothing is performed: the road centerline extracted through the above steps also needs to be smoothed, and the Bezier interpolation smoothing interface method in ArcEngine can be used for curve fitting.

[0161] For example, the road centerline extraction process is shown in the following figure: Figure 7 As shown in Figure 2. The source road data diagram is as follows: Figure 7 As shown in (a) in the figure, the schematic diagram of constructing the Delaunay triangle is as follows Figure 7 As shown in (b), the schematic diagram of extracting the center line based on the Delauany triangulation is as follows Figure 7 As shown in (c), the schematic diagram of the intersection road straightening process is as follows Figure 7 As shown in (d) in the figure, the schematic diagram of the road centerline smoothing process is as follows Figure 7 As shown in (e) in .

[0162] Furthermore, the road centerline effect diagram is as follows Figure 8 As shown, the dark line is the original two-lane road, and the light line is the extracted road centerline.

[0163] Step 2: Road fusion network construction.

[0164] In some embodiments, heterogeneous data are integrated through a unified mathematical basis, the original layer source information is retained, and in order to apply the requirements of the constraint surface weighted graph theory road network selection model, it is necessary to perform fusion network processing on multi-source road feature classes.

[0165] Specifically, the process of automatically implementing road fusion network construction includes:

[0166] (1) Generate an empty feature class using all road layer feature classes to be networked as templates (mathematical basis and corresponding fields);

[0167] (2) Traverse the feature classes of different layers one by one, add the corresponding features to the newly created empty feature class, and match and update the corresponding attribute information;

[0168] (3) Create a new FROMLAYER field and write the name value of the road feature source layer into it.

[0169] It is understandable that the main purpose of doing this is to track the source of the fused elements in the later comprehensive processing, to ensure that each feature in the fused road feature class has a corresponding layer source mark, and to be able to accurately and reasonably integrate the attribute values of the features when performing geometric processing on the road data in the later stage; at the same time, the corresponding geometric original state of the integrated road elements can be restored according to the FROMLAYER field, and the roads can be classified and extracted through the attribute values of this field, so that the road feature class after the comprehensive operation can be reasonably symbolized.

[0170] For example, the road fusion network diagram is as follows: Figure 9 shown.

[0171] Step 3: Handle road link breaks.

[0172] In some embodiments, in order to meet the requirements of the road network selection model based on the constraint surface weighted graph theory, the boundary lines of the merged multi-source road mesh are broken, and the corresponding two road elements at the intersection are disconnected.

[0173] For example, the schematic diagram of road broken link processing is as follows: Figure 10 shown.

[0174] Step 4: Delete overlapping road lines.

[0175] In some embodiments, a buffered polygon is generated for line features based on the cluster tolerance, completely contained overlapping features are identified through spatial queries, and overlapping features are deleted.

[0176] Step 5: Road breakpoint processing.

[0177] In some embodiments, corresponding roads with pseudo nodes or roads without pseudo nodes that are interrupted are connected at the breakpoints to form a new road network feature class, and attribute values of the connected road networks are integrated.

[0178] Specifically, for road segments with pseudo nodes, geometric connections and attribute value consistency processing are performed; for roads whose breakpoints are not pseudo nodes, corresponding geometric connections are performed, and the attribute values of the new connected road elements are taken as the average of the numerical attribute values of the two old roads before the merger or the same value of the non-numeric attribute values. If the attribute values of the corresponding fields of the two old roads are different and non-numeric, then both attribute values are written into the newly merged element, and are distinguished by the ID number and separated by ",". In the process of connecting the road breakpoints, the newly created elements are tracked by geometric processing using the newly created field attribute values, and the ID number of the corresponding road before the merger is recorded. After the integration is completed, the road is re-interrupted and the attribute value processing is performed.

[0179] For example, the pseudo node detection and automatic linking process flow chart is as follows: Figure 11 As shown, the road breakpoint connection diagram is as follows Figure 12 shown.

[0180] Step 6: Extract mesh boundary information.

[0181] In some embodiments, the road mesh is constructed by converting road line elements into road mesh surfaces. The specific steps are as follows:

[0182] 1) Use the DataManagementTools.FeatureToPolygon interface tool in ArcEngine to convert the road line feature class into a road mesh feature class;

[0183] 2) Add the BOUNADRY, AREA, and DENSITY fields to the newly generated road mesh feature class:

[0184] 3) Traverse the generated road mesh, calculate the area value of the corresponding road mesh and store it in the AREA area field attribute value;

[0185] 4) Use ArcEngine geometric feature attributes to extract the boundary lines of the road mesh, perform buffer analysis on the boundary lines of the road mesh, and generate buffer surface features;

[0186] 5) Perform overlay analysis on the buffer surface features and the boundary lines of the road mesh line feature class, find the road mesh boundary line corresponding to each mesh surface feature, and store the ID of the corresponding road mesh road boundary line in the BOUNADRY field attribute value to facilitate tracking and updating of road mesh boundary lines when merging meshes in the graph theory model later;

[0187] 6) Calculate the road density of the road mesh and store the corresponding calculated value in the DENSITY field attribute value.

[0188] Step 7: Extract suspension road information.

[0189] It should be noted that the structured objects of the road mesh topology relationship include not only the road mesh and its boundaries, but also the suspended roads inside and outside the road mesh. These suspended roads are divided into internal suspended roads and peripheral suspended roads. Based on the actual distribution of roads, peripheral suspended roads primarily refer to the outermost boundary roads of the integrated area, serving as bridges connecting the integrated area with the road networks in other areas. The selection of internal suspended roads is primarily determined by road length, grade, and mesh density.

[0190] In some embodiments, the steps for extracting the outermost hanging lines of a mesh are: first, merge all road meshes; then, through spatial analysis, find all road lines outside the boundaries of the merged road meshes and identify these roads as mesh-peripheral hanging roads. The main process for extracting hanging roads within a mesh is to traverse the road mesh and use the AE spatial query interface to find roads that fall within the mesh. The found roads are the mesh-internal hanging lines.

[0191] Step 8: Road attribute value integration.

[0192] In some embodiments, a new feature class is created to store the processing results. A new FROM field is created to track the elements in the comprehensive processing process, record the source information of the elements, establish the ID relationship between the elements in the new feature class and the original elements, and achieve dynamic integration through attribute mapping rules. Numerical attributes are averaged, and non-numeric attributes are merged and stored.

[0193] Step 9: Extract the road centerline.

[0194] In some embodiments, the road centerline is re-extracted after the road attribute values are integrated.

[0195] Step 10: Construct a road mesh structured topology model.

[0196] In some embodiments, the topology model constructs the topological relationship between the boundary lines of the road mesh and the suspended road groups.

[0197] For example, the topology model is represented in the form of an attribute table. Figure 13 It is the structured information representation of the road mesh boundary lines and suspension lines. Figure 14 It represents the structured information of the road mesh. Shape represents the geometric shape of the road mesh; Area represents the area of the road area; Boundary represents the boundary line of the road mesh area; Dangle represents unconnected or isolated line segments in the road mesh; and Density represents the density of the road mesh, reflecting the distribution of roads within a unit area.

[0198] Furthermore, the road mesh structure diagram is as follows Figure 15 As shown in the figure, the gray surface represents the road mesh, the light lines represent the road mesh boundary roads and the road mesh peripheral hanging roads, and the dark lines represent the road mesh internal hanging roads.

[0199] Step 11: Select characteristic road markings.

[0200] a. Select based on attribute value semantic constraints.

[0201] Graph-theoretic models prioritize geometric relationships when selecting roads. However, unlike geographic line features like contour lines, roads are line features with rich attribute data. Traditional graph-theoretic model road selection can be optimized using characteristic road constraints, leading to the development of a method for selecting characteristic roads based on semantic constraints of attribute values. This functionality is implemented by inputting relevant road names or keywords for road selection, or by using SQL conditional queries to query and select roads with specific semantics.

[0202] b. Select according to the spatial position constraint method.

[0203] Road selection is performed based on spatial positional constraints. This selection method mainly uses spatial analysis methods. It loads the relevant road accessory feature layer to perform spatial judgments such as proximity and inclusion, marks the relevant roads as feature roads, and then selects them. For example, it loads ferry point data, performs proximity analysis and query, and marks the roads connecting the ferry as feature roads to achieve the selection purpose.

[0204] c. Click Visual Selection in Manual Interaction.

[0205] According to the manual interactive click visual selection, this selection method is mainly aimed at the situation where the use of graph theory model selection may cause some roads to be discontinuous. If this situation occurs, the comprehensive results can be judged. If such road discontinuity is found, manual interactive click can be used again to select the relevant roads as feature road segments.

[0206] Step 12: Select the suspension road.

[0207] In some embodiments, all suspended roads are selected according to a minimum road length threshold, and roads with lengths less than the threshold are found. At the same time, it is determined whether they are characteristic roads. If so, they are retained; otherwise, they are discarded.

[0208] Optionally, for the internal hanging lines of the road mesh, according to the shortest road length expression conditions of the corresponding mapping specifications of the comprehensive target scale (for example, according to the provisions of the national basic scale map compilation specifications, the minimum expression length on the 1:25000 topographic map road map is 1 cm, that is, the actual road length is 250m), the road lines that are shorter than the specification length threshold and are not feature roads will be deleted.

[0209] Furthermore, the road mesh line density is determined. According to mapping standards, for road meshes with a line density threshold exceeding the specified threshold, the smallest and shortest dangling roads within the mesh are searched. If the dangling roads identified are not characteristic roads, they are marked and deleted. For dangling roads outside the road mesh, these road features are retained during the selection process, as they serve as bridges connecting the integrated regional road network with another regional road network.

[0210] Step 13: Select the road mesh boundary line.

[0211] In some embodiments, based on the road mesh line density threshold and the number of comprehensive road targets, non-feature roads with the smallest level and smallest length are discarded. All road meshes in the comprehensive area are extracted and re-sorted from smallest to largest in area to find the road mesh with the smallest area.

[0212] Furthermore, all roads that make up the smallest road mesh are extracted to find one or several roads with the lowest road grade. If there is only one road with the lowest grade, determine whether it is a feature road. If it is not a feature road, discard the road. Otherwise, continue to search for roads with low grades and short lengths. If the number is greater than 1, find the road with the shortest length and determine whether it is a feature road. If so, retain it, otherwise discard it.

[0213] Step 14: Detect and eliminate pseudo nodes.

[0214] In some embodiments, each road is traversed, and if the attributes of the current road and the adjacent road are consistent, the node between the two roads is considered to be a pseudo node, and the two roads are then connected.

[0215] Step 15: Road breakpoint recovery.

[0216] In some embodiments, meshes on both sides of the discarded road are merged, and the mesh topology information is updated. Furthermore, the number of remaining roads is calculated. If the target value is reached, the process exits; otherwise, the process proceeds to the step of extracting all road meshes within the integrated area and reordering them by area to find the road mesh with the smallest area.

[0217] For example, the road network data diagrams of various scales are as follows: Figure 16As shown in the figure. Among them, the 1:1000 original road network data diagram is as follows Figure 16 As shown in (a) in the figure, the schematic diagram of the road centerline data extracted at 1:1000 is as follows Figure 16 As shown in (b) in the figure, the schematic diagram of the integrated road network data at a scale of 1:10000 is as follows: Figure 16 As shown in (c) in the figure, the schematic diagram of the integrated road network data at a scale of 1:25000 is as follows: Figure 16 As shown in (d) in the figure, the schematic diagram of the integrated road network data at a scale of 1:50000 is as follows: Figure 16 As shown in (e) in the figure, the schematic diagram of road superposition data at different scales is as follows Figure 16 As shown in (f) in .

[0218] The road network comprehensive result information evaluation table includes a road selection comprehensive information table and a road simplification comprehensive information table. The road selection comprehensive information table is shown in Table 1 below:

[0219]

[0220] For example, the comprehensive information table of road simplification is shown in Table 2 below, and the simplification thresholds thereof are: 1m, 2.5m, and 5m respectively.

[0221]

[0222] Among them, the schematic diagram of the position relationship between the simplified road and the comprehensive front-source two-lane road is as follows: Figure 17 As shown in the figure, the enlarged schematic diagram of the position relationship between the simplified road and the comprehensive front-source two-lane road is shown in the figure. Figure 18 As shown. Among them, Figure 18 It includes two-lane roads and single-lane roads after centerline extraction, road selection and simplification.

[0223] For example, the attribute table of the road network with a scale of 1:1000 obtained by selecting and simplifying the local urban road network with a scale of 1:10000 is as follows: Figure 19 As shown in the figure, the road attribute data comparison diagram of the local urban road network with a scale of 1:1000 after road selection and road simplification is shown in the figure. Figure 20 As shown in the figure, control 1 is annotated with the road name of the corresponding single-line feature, and control 2 is annotated with the road name of the corresponding simplified single-line road.

[0224] Specifically, the flow chart of the constraint-based face weight graph theory road network selection model is as follows: Figure 21As shown in the figure, the road line feature and the road mesh surface feature are first obtained. Then, comprehensive parameters are set to select characteristic road markings. The road mesh is sequentially traversed to find the minimum hanging line in the mesh. It is determined whether the corresponding hanging line length is less than the comprehensive threshold. If so, the road feature is retained and the minimum hanging line in the mesh is searched again. If not, the road marking is deleted.

[0225] Furthermore, it is determined whether the number of remaining roads is greater than the comprehensive threshold of the square root model. If so, the road mesh is traversed sequentially, the road mesh line density is calculated, and it is determined whether the remaining line density is greater than the comprehensive threshold of the line density. If so, the hanging line with the minimum level and the shortest length is searched, and it is determined whether the hanging line is a feature road. If so, the road feature is retained, and the hanging line with the minimum level in the mesh is searched again. Otherwise, the road mark is deleted.

[0226] Afterwards, determine whether the remaining number is greater than the comprehensive threshold of the square root model. If so, find the road mesh with the smallest area, and then find the boundary line of the road mesh with the smallest area. Determine whether the number of minimum level edges is greater than 1. If not, delete the road mark. If so, find the minimum length edge among the minimum level edges, and determine whether the minimum length edge is a characteristic road. If so, retain the road feature and re-find the boundary line of the mesh with the smallest level. If not, delete the road mark.

[0227] Next, find another adjacent road network to merge, merge the two networks to create a new element network, and store it. Then, improve the attribute information of the boundary between the new and old faces, and find the starting point of the boundary line to be deleted. Determine whether the starting point is a graph theory breakpoint. If so, connect the starting point graph theory breakpoint to integrate the attribute information, update the merged road network boundary information, and then find the end point of the boundary line to be deleted. If not, directly find the end point of the boundary line to be deleted.

[0228] Next, determine whether the endpoint is a graph breakpoint. If so, connect the graph breakpoint at the endpoint, integrate attribute information, update the merged road network boundary information, and then determine whether the number of remaining roads is greater than the square root model comprehensive threshold. If not, directly determine whether the number of remaining roads is greater than the square root model comprehensive threshold. If the number of remaining roads is less than or equal to the square root model comprehensive threshold, the comprehensive road selection is completed. Otherwise, return to the step of finding the road network with the smallest area.

[0229] The comprehensive model for road network selection in the embodiment of the present application is a reasonable and effective comprehensive model. Practice has shown that: the algorithm takes into account the overall characteristics of the road network relatively well, and the network characteristics are well maintained; the selection using characteristic road constraints in the selection process maintains good connectivity for high-level roads, which improves the shortcomings of traditional graph theory-based model for road selection, which focuses more on considering geometric comprehensive constraints and pays less attention to the impact of road attribute values and other geographical factors on road selection; at the same time, the road mesh density constraints are taken into account in the selection process, so the difference in road mesh density after selection is also well maintained; for the comprehensive selection part of roads, the use of this system program can reduce the workload by 80% to 90% compared with manual comprehensive map making operations, while avoiding human errors in manual operations.

[0230] Guided by the principles of road network integration, this application example analyzes the structural characteristics of the road network, selects appropriate automatic road integration operators and models, implements a road network integration system through system design, conducts road integration case studies, and analyzes and evaluates the road integration quality. After integration, the structural characteristics of the road network and the differences in road network line density are reasonably maintained. The data quality, such as the correctness of the topological relationships between roads, the integrity of attribute values, and geometric accuracy, is relatively good. The road network integration system achieves excellent results in terms of adaptability, overall efficiency, and degree of automation. The road network integration system has considerable application value and can provide a reference for further research on road network integration.

[0231] See also Figure 22 The embodiment of the present application further provides a road network automatic integration device, which can implement the above-mentioned road network automatic integration method, and the device includes:

[0232] A marking module 2201 is used to mark characteristic roads based on initial road network structured information, where the initial road network structured information includes road mesh boundary lines and road mesh suspension lines;

[0233] The first integration module 2202 is configured to delete the road mesh hanging lines that are shorter than a minimum road length threshold and do not belong to the characteristic roads in the initial road network structured information, thereby obtaining the deleted first road network structured information;

[0234] The second integration module 2203 is configured to mark the first candidate road based on the initial mesh structured information, the first road network structured information, and the road mesh line density threshold, and delete the first candidate road with the lowest road grade and not belonging to the feature road in the first road network structured information to obtain the deleted second road network structured information, wherein the initial road network structured information includes road grade information and road length information;

[0235] The third integration module 2204 is configured to mark the second candidate roads based on the initial mesh structured information and the second road network structured information, delete the second candidate roads that have the lowest road grade and are not feature roads in the second road network structured information, and obtain the deleted third road network structured information;

[0236] The merging module 2205 is used to merge meshes based on the third road network structured information to obtain target mesh structured information and target road network structured information.

[0237] The present application also provides an electronic device comprising a memory and a processor, wherein the memory stores a computer program, and the processor executes the computer program to implement the above-mentioned method for automatic road network integration. The electronic device can be any intelligent terminal, such as a tablet computer or an in-vehicle computer.

[0238] See also Figure 23 , Figure 23 The hardware structure of an electronic device according to another embodiment is shown. The electronic device includes:

[0239] The processor 2301 can be implemented using a general-purpose CPU (Central Processing Unit), a microprocessor, an application-specific integrated circuit (ASIC), or one or more integrated circuits, and is used to execute relevant programs to implement the technical solutions provided in the embodiments of the present application;

[0240] The memory 2302 can be implemented in the form of a read-only memory (ROM), a static storage device, a dynamic storage device, or a random access memory (RAM). The memory 2302 can store an operating system and other application programs. When the technical solutions provided in the embodiments of this specification are implemented through software or firmware, the relevant program code is stored in the memory 2302 and is called by the processor 2301 to execute the road network automatic integration method of the embodiments of this application.

[0241] Input / output interface 2303, used to implement information input and output;

[0242] Communication interface 2304, used to implement communication interaction between this device and other devices, which can be achieved through wired means (such as USB, network cable, etc.) or wireless means (such as mobile network, WiFi, Bluetooth, etc.);

[0243] Bus 2305 , which transmits information between various components of the device (e.g., processor 2301 , memory 2302 , input / output interface 2303 , and communication interface 2304 );

[0244] The processor 2301 , the memory 2302 , the input / output interface 2303 and the communication interface 2304 are connected to each other in communication within the device via the bus 2305 .

[0245] An embodiment of the present application also provides a computer-readable storage medium, which stores a computer program. When the computer program is executed by a processor, a method for automatic road network integration is implemented.

[0246] It can be understood that the contents of the above method embodiments are applicable to device embodiments, equipment embodiments and storage medium embodiments. The functions specifically implemented by this storage medium embodiment are the same as those of the above method embodiments, and the beneficial effects achieved are also the same as those achieved by the above method embodiments.

[0247] The memory, as a non-transient computer-readable storage medium, can be used to store non-transient software programs and non-transient computer executable programs. In addition, the memory may include a high-speed random access memory and may also include a non-transient memory, such as at least one disk storage device, a flash memory device, or other non-transient solid-state storage device. In some embodiments, the memory may optionally include a memory remotely arranged relative to the processor, and these remote memories may be connected to the processor via a network. Examples of the above-mentioned network include, but are not limited to, the Internet, an intranet, a local area network, a mobile communication network, and combinations thereof.

[0248] The preferred embodiments of the present invention are described above with reference to the accompanying drawings, but are not intended to limit the scope of the present invention. Any modifications, equivalent substitutions, and improvements made by those skilled in the art without departing from the scope and essence of the present invention should be within the scope of the present invention.

Claims

1. A method for automatic road network integration, characterized in that: The method comprises the following steps: Marking characteristic roads based on initial road network structured information, wherein the initial road network structured information includes road mesh boundary lines and road mesh suspension lines; Deleting the road mesh suspension lines that are shorter than a minimum road length threshold and do not belong to the characteristic roads in the initial road network structured information, to obtain first road network structured information after deletion; marking a first candidate road based on the initial mesh structured information, the first road network structured information, and a road mesh line density threshold, deleting the first candidate road having the lowest road grade in the first road network structured information and not belonging to the feature road, to obtain second road network structured information after deletion, wherein the initial road network structured information includes road grade information and road length information; marking a second candidate road based on the initial mesh structured information and the second road network structured information, deleting the second candidate road having the lowest road grade in the second road network structured information and not belonging to the feature road, to obtain third road network structured information after deletion; Performing mesh merging based on the third road network structured information to obtain target mesh structured information and target road network structured information; The mesh merging based on the third road network structured information to obtain target mesh structured information and target road network structured information includes: Performing mesh merging based on the third road network structured information to obtain current mesh structured information and current road network structured information after mesh merging; Obtaining the target road quantity and calculating the current road quantity of the current road network structured information; If the current number of roads is greater than the target number of roads, the current road network structured information is used as the second road network structured information, the current mesh structured information is used as the initial mesh structured information, and the process returns to the step of marking the second candidate road based on the initial mesh structured information and the second road network structured information, until the current number of roads is less than or equal to the target number of roads. If the current number of roads is less than or equal to the target number of roads, the current mesh structured information is used as the target mesh structured information, and the current road network structured information is used as the target road network structured information.

2. The method according to claim 1, characterized in that The marking of characteristic roads based on the initial road network structured information includes one of the following: Selecting and marking characteristic roads based on the initial road network structured information using a graph theory model through attribute value semantic constraints; Alternatively, a spatial analysis method is used to analyze the initial road network structured information to select and mark characteristic roads; Alternatively, in response to the first instruction, the initial road network structured information is displayed on the map page, and in response to the road selection instruction, the characteristic road selected by the user is displayed on the map page.

3. The method according to claim 1, characterized in that The road mesh suspension lines include road mesh internal suspension lines and road mesh external suspension lines. Deleting the road mesh suspension lines that are less than a minimum road length threshold and do not belong to the characteristic roads in the initial road network structured information to obtain the deleted first road network structured information includes: retaining the road mesh external suspension lines in the initial road network structured information; The road mesh internal hanging lines that are less than a minimum road length threshold and do not belong to the characteristic roads are deleted from the initial road network structured information to obtain the deleted first road network structured information.

4. The method according to claim 1, wherein The first candidate road is marked based on the initial mesh structured information, the first road network structured information, and the road mesh line density threshold, and the first candidate road having the lowest road grade in the first road network structured information and not belonging to the feature road is deleted to obtain the deleted second road network structured information, wherein the initial road network structured information includes road grade information and road length information, including: Calculating the current road mesh line density of each mesh based on the initial mesh structure information and the first road network structure information; Determine a mesh whose current road mesh line density is greater than the road mesh line density threshold as a candidate mesh, mark a road in the candidate mesh as a first candidate road, and select the first candidate road with the lowest road grade as a first pre-selected road; If the first pre-selected road includes only a single road, and the first pre-selected road does not belong to the characteristic road, deleting the first pre-selected road from the first road network structured information to obtain second road network structured information after deletion; If the first pre-selected roads include multiple roads, the road with the shortest length among the first pre-selected roads is determined as the first selected road. If the first selected road does not belong to the characteristic road, the first selected road is deleted from the first road network structured information to obtain the deleted second road network structured information.

5. The method according to claim 1, wherein The initial mesh structure information includes a mesh area, and marking a second candidate road based on the initial mesh structure information and the second road network structure information includes: Determining the road mesh with the smallest mesh area based on the initial mesh structural information; Based on the second road network structured information, the roads constituting the road mesh with the smallest mesh area are marked as second candidate roads.

6. The method according to claim 1, characterized in that The method further comprises: Obtain source road data; Extracting a road centerline based on the source road data using a Delaunay triangulation method; Fusing the road centerlines of multiple road layers to obtain fused road data; Performing link breaking processing, overlapping line deletion processing, and road breakpoint processing on the fused road data to obtain original road information; Converting road line elements into road mesh surfaces based on the original road information, and determining road meshes and road mesh boundary lines; Determining a road mesh internal suspension line and a road mesh external suspension line based on the original road information and the road mesh; A topological relationship model is constructed based on the original road information, the road mesh, the road mesh boundary line, the road mesh internal suspension line and the road mesh external suspension line. The topological relationship model includes initial road network structured information and initial mesh structured information.

7. A road network automatic integration device, characterized in that: The device comprises: a marking module, configured to mark characteristic roads based on initial road network structured information, wherein the initial road network structured information includes road mesh boundary lines and road mesh suspension lines; A first integration module is configured to delete the road mesh hanging lines that are shorter than a minimum road length threshold and do not belong to the characteristic roads in the initial road network structured information, thereby obtaining first road network structured information after deletion; a second integration module, configured to mark first candidate roads based on the initial mesh structured information, the first road network structured information, and a road mesh line density threshold, and delete the first candidate roads having the lowest road grade in the first road network structured information and not belonging to the feature roads, to obtain second road network structured information after deletion, wherein the initial road network structured information includes road grade information and road length information; a third integration module, configured to mark second candidate roads based on the initial mesh structured information and the second road network structured information, delete the second candidate roads having the lowest road grade in the second road network structured information and not belonging to the feature roads, and obtain third road network structured information after deletion; a merging module, configured to merge meshes based on the third road network structured information to obtain target mesh structured information and target road network structured information; The merging module is specifically used for: Performing mesh merging based on the third road network structured information to obtain current mesh structured information and current road network structured information after mesh merging; Obtaining the target road quantity and calculating the current road quantity of the current road network structured information; If the current number of roads is greater than the target number of roads, the current road network structured information is used as the second road network structured information, the current mesh structured information is used as the initial mesh structured information, and the process returns to the step of marking the second candidate road based on the initial mesh structured information and the second road network structured information, until the current number of roads is less than or equal to the target number of roads. If the current number of roads is less than or equal to the target number of roads, the current mesh structured information is used as the target mesh structured information, and the current road network structured information is used as the target road network structured information.

8. An electronic device, characterized in that: The electronic device includes a memory and a processor, the memory stores a computer program, and the processor implements the method according to any one of claims 1 to 6 when executing the computer program.

9. A computer-readable storage medium storing a computer program, characterized in that: When the computer program is executed by a processor, the method according to any one of claims 1 to 6 is implemented.

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